Process for the production of hydrogen peroxide

Abstract

Hydrogen peroxide is produced by reacting hydrogen and oxygen in the presence of a noble metal catalyst in a liquid reaction medium, the reaction being performed in the presence of a sulfuric acid alkyl ester. In the presence of sulfuric acid alkyl esters the noble metal catalyst exhibits a high and lasting activity for the formation of hydrogen peroxide with an elevated selectivity of hydrogen peroxide formation relative to the hydrogen used. Solutions of hydrogen peroxide in methanol obtainable by the process are suitable for use for the epoxidation of olefins.

1. A process for producing hydrogen peroxide by reacting hydrogen and oxygen in the presence of a noble metal catalyst in a liquid reaction medium, wherein the reaction is performed in the presence of a sulfuric acid alkyl ester. 
     
     
       2. The process of  claim 1 , wherein the sulfuric acid alkyl ester is a sulfuric acid dialkyl ester, a sulfuric acid monoalkyl ester or an alkali metal or ammonium salt of a sulfuric acid monoalkyl ester. 
     
     
       3. The process of  claim 2 , wherein the alkyl radical in the sulfuric acid alkyl ester is chosen from the group consisting of: methyl; ethyl; n-propyl; and n-butyl. 
     
     
       4. The process of  claim 2 , wherein the alkyl radical in the sulfuric acid alkyl ester is methyl. 
     
     
       5. The process of  claim 1 , wherein the reaction is performed in an aqueous, aqueous-organic or organic reaction medium containing a bromide and/or iodide in dissolved form. 
     
     
       6. The process of  claim 5 , wherein the aqueous-organic or organic reaction medium comprises a solvent selected from the group consisting of: methanol; ethanol; n-propanol and n-butanol. 
     
     
       7. The process of  claim 5 , wherein the aqueous-organic or organic reaction medium comprises methanol. 
     
     
       8. The process of  claim 5 , wherein the sulfuric acid alkyl ester is a sulfuric acid dialkyl ester, a sulfuric acid monoalkyl ester or an alkali metal or ammonium salt of a sulfuric acid monoalkyl ester. 
     
     
       9. The process of  claim 8 , wherein the alkyl radical in the sulfuric acid alkyl ester is chosen from the group consisting of: methyl; ethyl; n-propyl; and n-butyl. 
     
     
       10. The process of  claim 8 , wherein the alkyl radical in the sulfuric acid alkyl ester is methyl. 
     
     
       11. The process of  claim 1 , wherein the reaction is performed with a non-explosive gas mixture containing hydrogen and oxygen. 
     
     
       12. The process of  claim 1 , wherein the noble metal catalyst comprises metallic palladium on a support. 
     
     
       13. The process of  claim 12 , wherein the sulfuric acid alkyl ester is a sulfuric acid dialkyl ester, a sulfuric acid monoalkyl ester or an alkali metal or ammonium salt of a sulfuric acid monoalkyl ester. 
     
     
       14. The process of  claim 13 , wherein the alkyl radical in the sulfuric acid alkyl ester is chosen from the group consisting of: methyl; ethyl; n-propyl; and n-butyl. 
     
     
       15. The process of  claim 13 , wherein the alkyl radical in the sulfuric acid alkyl ester is methyl. 
     
     
       16. The process of  claim 1 , wherein the reaction is performed in a reactor in which the noble metal catalyst is arranged in the form of one or more fixed beds and a gas mixture containing hydrogen and oxygen is passed through the reactor in such a way that, at no point, is the surface of the reactor permanently in contact with the gas mixture being passed through the reactor. 
     
     
       17. The process of  claim 16 , wherein:
 a) the reaction is performed with a non-explosive gas mixture containing hydrogen and oxygen; 
 b) the noble metal catalyst comprises metallic palladium on a support; 
 c) the sulfuric acid alkyl ester is a sulfuric acid dialkyl ester, a sulfuric acid monoalkyl ester or an alkali metal or ammonium salt of a sulfuric acid monoalkyl ester. 
 
     
     
       18. The process of  claim 17 , wherein the alkyl radical in the sulfuric acid alkyl ester is chosen from the group consisting of: methyl; ethyl; n-propyl; and n-butyl.